Marathon world record-holder Paula Radcliffe will run the first event to be staged at London's Olympic Stadium since the 2012 Games later today.
Radcliffe, who was unable to compete at the London Olympics due to injury, will join a host of sporting stars including Olympic gold medallists Sir Chris Hoy and Victoria Pendleton, who are more used to cycling than running.
They will be among the 12,500 people taking part in the five-mile (eight-kilometre) National Lottery Anniversary Run, in which competitors will complete the final 328 yards (300m) on the Olympic Stadium's track.
Radcliffe has predicted the event would "recapture the spirit of the London 2012".
More top news
A group of friends in Haverhill have left one of their mates with a fractured spine after a prank with a home-made ejector seat went wrong
Temperatures will remain low for most of the country as Britain battles against wintry showers, snow and gales this afternoon.
A giant panda has been caught in camera breaking iron bars and moving into the other cell to have a taste of milk in the next cell.